Comparison of the BioRad Variant and Primus Ultra2 high-pressure liquid chromatography (HPLC) instruments for the detection of variant hemoglobins

Introduction: Hemoglobin variants are a result of genetic changes resulting in abnormal or dys-synchronous hemoglobin chain production (thalassemia) or the generation of hemoglobin chain variants such as hemoglobin S. Automated high-pressure liquid chromatography (HPLC) systems have become the method of choice for the evaluation of patients suspected with hemoglobinopathies. Methods: In this study, we evaluated the performance of two HPLC methods used in the detection of common hemoglobin variants: Variant and Ultra2. Results: There were 377 samples tested, 26% (99/377) with HbS, 8.5% (32/377) with HbC, 20.7% (78/377) with other hemoglobin variant or thalassemia, and 2.9% with increased hemoglobin A₁c. The interpretations of each chromatograph were compared. There were no differences noted for hemoglobins A₀, S, or C. There were significant differences between HPLC methods for hemoglobins F, A₂, and A₁c. However, there was good concordance between normal and abnormal interpretations (97.9% and 96.2%, respectively). Conclusion: Both Variant and Ultra2 HPLC methods were able to detect most common hemoglobin variants. There was better discrimination for fast hemoglobins, between hemoglobins E and A₂, and between hemoglobins S and F using the Ultra2 HPLC method.